The development of a unified European HRC hardness scale

Abstract

An intercomparison of measurements on hardness scales was carried out on behalf of the Commission of the European Communities by six national laboratories of the Member States. In order to assess the influences of different error sources, the laboratories measured the Rockwell B, Rockwell C and Vickers hardnesses of reference plates, using both common indenters and their respective national indenters. The results of the Rockwell C measurements are presented. The investigations led to a harmonised European HRC scale, initially based on the results of four laboratories. Three laboratories undertook a refinement of the scale. Due to inconsistent results from one institute, the discussion of the results and the final definition of the European HRC scale is not yet complete.